Deck plank and method of production

ABSTRACT

A deck plank is co-extruded from an extrusion die which receives molten plastics materials supplied from three separate plastic extruders to provide the plank with opposite sides having different colors. Preferably, the base plank is extruded from a lower cost material such as reground scrap polyvinylchloride (PVC), and thin PVC cap layers are co-extruded on opposite sides of the base plank in different colors. Opposite edges of each plank have longitudinally extending grooves for receiving hidden fasteners in the form of screws extending through short flat tie pieces or a continuous sealing tie strip projecting into the opposing grooves of adjacent planks.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a deck plank of extruded plastics material and its assembly onto a supporting structure, for example, of the general type disclosed in U.S. Pat. No. 6,301,842 which issued to the Assignee of the present invention. As disclosed in this patent, it is known to extrude deck planks from a plastics material such as polyvinylchloride (PVC) and wherein the base plank is extruded of a less expensive reground or scrap plastics material or PVC, and the top surface is formed by a thin co-extruded capstock layer of more expensive or virgin PVC. The capstock layer provides the top surface with a predetermined durable color and a top pattern surface, for example, a knurl surface with a raised diamond pattern. It has also been found desirable to provide a deck plank which is reversible and with opposite sides having different colors. For example, one side of the deck plank may be gray or off white, and the opposite side may have a color of light brown or a color and texture similar to a treated wood deck plank. It is further desirable to provide for simple and quick assembly of extruded deck planks with hidden fasteners and sometimes with a water-tight seal between adjacent planks so that rain water runs off the ends of the assembled planks.

SUMMARY OF THE INVENTION

[0002] The present invention is directed to an improved deck plank of extruded plastics material and which provides all of the desirable features mentioned above. In addition, the deck plank of the invention provides a high strength/weight ratio and substantially reduces a dealers inventory of deck planks since each deck plank is offered with side surfaces in two different colors and may be simply reversed by the customer for selecting between the colors. It is to be understood that the term “deck plank” as used herein includes any plank which is used for supporting people or articles, such as a plank used for making boat docks or for making platforms of all types.

[0003] In general, an extruded deck plank constructed in accordance with the invention includes parallel spaced side walls integrally connected by spaced transverse walls which are preferably perpendicular to the side walls. The transverse walls forming opposite edge walls of the deck plank define longitudinally extending slots or grooves within the center of the plank so that the plank is symmetrical about a reference plane extending through the grooves. The side walls of the deck plank are co-extruded with a capstock layer of plastics materials which are supplied from separate extruders to provide the opposite side walls with side surfaces of different colors, thereby permitting the customer or consumer to select between the two colors for the color of the top surface of the deck.

[0004] Preferably, the base deck plank is extruded of a less expensive reground scrap material, and the different colored cap layers are extruded of the virgin plastics material with the cap layers extending along the opposite edge walls to the center grooves. When the deck planks are assembled on a supporting frame structure, such as parallel spaced joists, short key or tie pieces or strips project into the opposing grooves of adjacent planks and provide a spacer between the planks. The tie pieces or strips are extruded with flexible fins which provide for a water-tight seal between adjacent deck planks.

[0005] Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a perspective view of a deck plank constructed in accordance with the invention and with a middle portion removed to illustrate an indefinite length;

[0007]FIG. 2 is an end view of the deck plank shown in FIG. 1;

[0008]FIG. 3 is a fragmentary section illustrating a plurality of the deck planks shown in FIG. 1 installed on a supporting structure; and

[0009]FIG. 4 is an enlarged fragmentary section of the deck plank shown in FIGS. 1-3 and with a tie piece or strip exploded therefrom.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010]FIGS. 1 and 2 illustrate a deck plank 10 which is co-extruded from three different plastics materials, such as PVC materials, and includes a pair of side walls 12 integrally connected by perpendicular transverse walls including intermediate webs or walls 14 and opposite edge walls 16. Each of the edge walls 16 includes a longitudinally extending U-shaped portion 18 defining a corresponding slot or groove 21. The grooves 21 are within the center portions of the edge walls 16 so that the plank 10 is symmetrical about a center reference plane P extending through the center of the grooves 21. As shown in FIGS. 1 and 2, each of the side walls 12 is extruded with parallel spaced traction grooves 23 which are located in longitudinal alignment with the interconnecting intermediate connecting walls 14. The traction grooves 23 also eliminate the appearance of any sink lines in the side walls 12 due to the intermediate walls 14.

[0011] Referring to FIG. 4, each of the side walls 12 and the connecting portions of the edge walls 16 down to the grooves 21 have corresponding base layers 26 and 27 which are integrally extruded with the intermediate walls 14 and the U-shaped portions 18 to form a base plank. The base layers 26 and 27 are co-extruded with thinner capstock or cap layers 32 and 34, respectively, and the cap layers 32 and 34 are supplied from separate corresponding extruders which extrude plastics materials or PVC of different colors so that the outer surfaces of the opposite side walls 12 have different colors. For example, cap layers for one side wall 12 and adjoining edge walls 16 may be gray or off white, and the cap layers for the opposite side wall 12 and adjoining edge walls 34 may be tan or clay or a color resembling treated wood. Preferably, the inner base layers 26 and 27, the U-shaped portions 18, and the intermediate walls 14, forming the base plank, are extruded of a less expensive reground scrap material or PVC, and the cap layers 32 and 34 are extruded of a virgin plastics material or PVC. The side walls 12 and the end walls 16 have a total predetermined thickness, for example, between 0.080 and 0.090″, and the cap layers 32 and 34 have a thickness of about 0.025″.

[0012] Referring to FIG. 3, a series of deck planks 10 of a predetermined length, for example 12 feet, are installed on a supporting structure, for example, in the form of parallel spaced wood joists 45. A C-channel strip 47 is first mounted on the joists 45 with suitable fasteners (not shown). The C-channel 47 is preferably formed of extruded plastics material or PVC and may have a height as shown in FIG. 3 to project into a slot 21 of the first deck plank 12. The C-channel may also have a height which covers the entire edge wall 16 of the plank 12 and overlaps the top surface of the top wall 12, thereby covering the slot 21 within the plank. After the first plank 12 is inserted into the C-channel, a retaining piece or strip 50 is inserted into the groove 21 on the opposite edge of the plank. A fastener, for example, in the form of a self-threading screw 52, is inserted on a diagonal through the strip 50 and the corner of the plank and into the each wood joist 45.

[0013] As shown in FIG. 4, the retaining strip 50 is preferably extruded from a plastics material such as polypropylene and includes a V-shaped center portion 54, opposite side wing or flange portions 56 and a vertical depending spacer portion 58. Flexible sealing fins 62 are extruded on the outer edges of the flange portions 56, and small V-shaped grooves 64 are extruded in the portion 54 to facilitate starting the self- tapping screws 52. The retaining strips may be in short sections, for example, having a length of 1¾″ and are similar to the retaining biscuits disclosed in U.S. Pat. No. 6,402,415. The strips 50 may also be continuous along the entire length of the plank 12. When the strips 50 are continuous and are inserted as shown in FIG. 3, the flexible sealing fin 62 forms a water-tight seal between the strip and the plank. Similarly, when the next adjacent plank 10 is installed, as shown in FIG. 3, the strip forms a water-tight seal with the adjacent plank, and the spacer portion 58 of the strip forms the proper spacing between the adjacent planks. With the water-tight seal between adjacent planks, rain water on the planks flows to the ends of the planks and not through the planks.

[0014] When an edge wall 16 is exposed along an edge portion of the deck, for example, at a series of steps, an extruded cover strip 70 (FIG. 3) having a T-shaped cross-sectional configuration, is inserted into the corresponding groove 21 with sufficient interference fit to retain the strip. Prior to inserting the strip, a fastener or self-threading screw 52 is inserted diagonally through the lower portion of the outer plank 10. Small V-shaped grooves 72 are extruded at the entrance of the U-shaped portions 18 of each plank 10 to facilitate starting a diagonal screw 52 when a retaining strip 50 is not required.

[0015] From the drawings and the above description, it is apparent that a deck plank constructed in accordance with the present invention and its installation provides desirable features and advantages. For example, the deck plank 10, with its side walls 12 and edge walls 16 co-extruded with capstock layers of different colors, provides the consumer or customer with a selection of one of the two colors for use as the top surface of the deck plank and also reduces the inventory required by a dealer who stocks the deck planks, thereby saving inventory expense. In addition, the grooves 21 in opposite edge walls 16 provide for receiving the hidden fasteners or tie strips 50 which provide for quickly installing the deck planks 10. Furthermore, when continuous tie strips 50 are used between adjacent deck planks, the flexible sealing fins 62 provide for continuous water-tight seal between the adjacent deck planks along the length of the planks so that water does not drain through the planks between the opposing edge walls 16 of adjacent planks and onto objects below. The V-shaped portions 54 of each strip 50 and the guide grooves 64 and 72 provide for convenient and precision installation of the strip 50 with the self threading screws 52.

[0016] While the deck plank herein described and its method or construction and assembly constitute a preferred embodiment of the invention, it is to be understood that the invention is not limited to the precise plank and method described, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims. 

What is claimed is:
 1. A deck plank comprising an elongated extrusion of plastics material, said extrusion having substantially parallel spaced opposite side walls integrally connected by a series of spaced transverse walls, and said opposite side walls have corresponding side surfaces formed by different color plastics material.
 2. A deck plank as defined in claim 1 wherein said opposite side walls have co-extruded cap layers of plastics material in different colors.
 3. A deck plank as defined in claim 1 wherein said transverse walls include longitudinally extending opposite edge walls each defining having a U-shaped portion a longitudinally extending groove.
 4. A deck plank as defined in claim 3 and including a longitudinally extending tie strip projecting into at least one of said grooves and adapted to project into said groove of an adjacent said plank.
 5. A deck plank as defined in claim 4 wherein said tie strip has at least one longitudinally extending flexible fin forming a generally fluid-tight seal between said strip and said plank.
 6. A deck plank as defined in claim 1 wherein said transverse walls extend generally perpendicular to said side walls.
 7. A deck plank as defined in claim 1 wherein said side walls define longitudinally extending and parallel space traction grooves within said side surfaces.
 8. A deck plank as defined in claim 1 wherein said transverse walls include longitudinally extending opposite edge walls defining corresponding longitudinally extending grooves, and said plank is symmetrical about a center reference plane extending parallel to said side surfaces through said grooves.
 9. A deck plank as defined in claim 8 wherein said opposite side walls have co-extruded cap layers of plastics material in different colors, and said cap layers extend along said edge walls to said grooves.
 10. A deck plank comprising an elongated extrusion of plastics material, said extrusion having substantially parallel spaced opposite side walls integrally connected by a series of spaced transverse walls, and said transverse walls including longitudinally extending opposite edge walls each having a U-shaped portion defining a longitudinally extending groove.
 11. A deck plank as defined in claim 10 wherein said opposite side walls have co-extruded cap layers of plastics material in different colors.
 12. A deck plank as defined in claim 10 and including a longitudinally extending tie strip projecting into at least one of said grooves and adapted to project into said groove of an adjacent said plank.
 13. A deck plank as defined in claim 12 wherein said tie strip has at least one longitudinally extending flexible fin forming a generally fluid-tight seal between said strip and said plank.
 14. A deck plank as defined in claim 12 wherein said tie strip has a V-shaped center portion connecting co-planar flange portions.
 15. A deck plank as defined in claim 14 wherein said V-shaped center portion of said tie strip has small grooves to facilitate use of self-threading fastening screws.
 16. A deck plank as defined in claim 10 wherein said plank is symmetrical about a center reference plane extending parallel to said side surfaces through centers of said grooves.
 17. A deck plank as defined in claim 10 wherein said opposite side walls have co-extruded cap layers of plastics material in different colors, and said cap layers extend along said edge walls to said grooves.
 18. A deck plank as defined in claim 10 wherein each of said edge walls has minor grooves adjacent the corresponding said U-shaped portion to facilitate use of self-threading fastening screws. 